It is known to provide flexible polymeric film packages which have an openable and resealable seal. In such packages, a slit is formed through one side of the enclosed package to provide an opening to the package. A further strip of flexible polymeric film material is adhered to the outer surface of the package adjacent the slit with a free longitudinal edge overlying the slit. A narrow strip of pressure-sensitive adhesive is provided adjacent the free longitudinal edge along the length of the slit so as to releasably engage the film on one lateral side of the slit while the strip is permanently adhered to the film on the other lateral side of the slit. In this way, access to the contents of the package may be attained by peeling apart the free edge of the strip and the underlying film along the line of adhesive. Following removal of the desired contents, the package may be temporarily resealed by pressing the separated films together along the line of the adhesive.
While such an arrangement is satisfactory with respect to opening and resealing packages to permit access to the contents of the package only when desired, no provision is made to ensure that a package displayed, for example, on a supermarket shelf, has not been opened, part of the contents removed and the package resealed. In addition, the structure requires a separate strip of material and slitting and adhering operations to be effected.